I downloaded VEEAM FastSCP and notice no where does it claim compatibility with ESXI 5.0.

I tried it out last night and it caused off behavior on my network.

I had 3 ESXI servers, 2 on 1 subnet, another on a different subnet but with inter subnet routing turned on. I connected to all 3 servers and tried to copy a small VM from one server to another, across subnets.

After a few minutes I had seen enough from a performance standpoint and hit cancel, but it would not cancel, so I closed out the app. Afterwards the entire network was shot, painfully slow until I rebooted the 2 ESXI hosts and the machine I used to copy the VM which was on the 3rd ESXI host.

Maybe it was a fluke, maybe it wasn't but it spooked me a bit.

I had converted 2 physical and 1 VM into another ESXI server as a temporary host. Then I was consolidating and migrating back. Turns out the server had a bad HD and I'm waiting for replacement so I put the temporary server in for the customer.

Since I have to copy 3 VM's back over I can just use FastSCP to do so, right? Put both ESXI servers on the network, shut down the VMs, use a 3rd device to copy them. When they are on the new host just go into the datastore and pick whatever file it is that allows the Add to Inventory option, correct?

I've just been playing with FastSCP for a move I'm planning on this Saturday and noticed the same issue you describe. Force it closed and notice that the network is still pushing traffic. I went into VSphere Client and saw on the bottom on the event log that the file copy was still running, so it appears as though the task runs on the server independently of the FastSCP software?